3-Layer Design for the Filter Media: A: Non-woven Cloth--remove big impurities. B: Activated Carbon Fiber--good absorption ability to odor, smoke, VOC, etc. C: Activated Carbon Sponge--high capacity to contaminants. Compared to the original single-layer filter, the multi-layer design has a superior absorption effect. AF005 can filter a large range of impurities of different particle sizes. 28 times more powerful than baking soda. The absorption rate of this filter brand is up to 240% higher than the original filter brand. It is recommended that you replace the filter every 6 months for maximum result.